The present invention relates to a shut-off device for protection against explosions in a pipe-line.
A shut-off device for protection against explosions of this type is known for example from DE-A-198 21 756. This specification discloses a slide valve plate for rapid shutting of pipe-lines, connected to a piston slidable within a cylinder and actuated by a pressure medium. The pressure medium is supplied from an external pressure reservoir to a working chamber in the cylinder via a closing valve. As a flame detected in the pipe-line propagates or a sudden pressure rise is suddenly detected, the closing valve opens, the piston is actuated and the slide valve plate, which is movable transversely to the direction of flow, is brought into the closed position within the shortest possible time, making it possible to prevent flame propagation and thus an explosion. Such shut-off devices for protection against explosion are used especially in chemical or foodstuffs plants but also in mining, cement, textile and wood-processing plants where dust explosions can occur, triggered for example by a spark, friction, plant overheating etc. The disadvantage of these devices is, as a rule, that they take up a relatively great deal of space and their construction and assembly are complicated.